But they have lived in the United States for years, and law enforcement officials remain uncertain why they might have set explosives near the finish line of Boston’s iconic footrace and whether they have ties to any international terrorist organization.
Law enforcement sources identified the suspect killed overnight in a shootout with police as Tamerlan Tsarnaev, 26, who was born in Russia. His younger brother Dzhokhar A. Tsarnaev, 19, born in Kyrgyzstan, fled the scene and on Friday was the subject of a massive manhunt in the Boston suburbs.
According to NBC News, the Tsarnaev brothers entered the US with family in 2002 or 2003. Tamerlan Tsarnaev became a permanent resident in 2007.
Other reports indicated that the Tsarnaev family had stayed for a time in Kazakhstan prior to their emigration to America.
Tamerlan was “Suspect No. 1” in the photos and video made public by the FBI on Thursday. He is seen in these images wearing a dark coat and a dark-colored baseball cap with a white stripe.
The elder brother was studying or has studied at Bunker Hill Community College, and hoped to be an engineer. He was an avid boxer who hoped to earn US citizenship by participating in the Olympics for the United States.
An album of images of Tamerlan Tsarnaev shot by photographer Johannes Hirn made this point with its title: “Will Box for Passport.”
“Unless his native Chechnya becomes independent, Tamerlan says he would rather compete for the United States than for Russia,” Mr. Hirn wrote in one caption.
Other captions depict the elder Tsarnaev as a Muslim who abstains from alcohol and is bewildered by the immorality of the surrounding American culture.
As Foreign Policy Magazine blogger David Kenner notes, at the time the photos were taken Tamerlan’s life seemed pretty good. He was enrolled in school and boxing and had a pretty half-Italian half-Portuguese girlfriend who had converted to Islam for him, according to a caption in the Hirn photo album.
“At some point, though, it all went wrong. In 2009, Tamerlan was arrested for domestic assault and battery after assaulting his girlfriend. The reasons for his descent into terrorism after that will no doubt be clear soon,” writes Mr. Kenner.
As for Dzhokhar Tsarnaev, he was a student at Cambridge Rindge and Latin School, at least for a time. Classmates speak of him as athletic and popular but quiet. He is a wrestler. He is currently enrolled at University of Massachusetts, Dartmouth.
According to a contemporaneous account on Boston.com, the city of Cambridge awarded Dzhokhar a $2,500 scholarship in 2011. Recipients of the scholarships, which are funded by local businesses, were honored in a May ceremony at Cambridge City Hall.
The Tsarnaev brothers lived in Cambridge with family members. Live news reports on Friday morning indicated that police searched the residence and exited with at least one female who appeared to be cooperating with their efforts.
In Moscow, local media indicated that the two men were from a family of refugees. The director of a school where they studied in 2001 said they came from Kirgizia, and that the family included two sisters.
Dzhokhar Tsarnaev has a page on VKontakte, a Russian social media site, where he says that his ideology is Islam and his aims in life are career and money. Time stamps on the site indicate that he checked in as late as 5 a.m. Moscow time on Friday.
The editor in chief of Echo Moskvi radio, Alexey Varfolomeev, said that possibly Dzhokhar was named in honor of Dzhokhar Dudaev, a Chechen president who was killed by Russian special services.
Back in the United States, former State Department spokesman Philip J. Crowley said all this emerging information reinforces the understanding of the evolving terrorist threat, which is decentralized, unpredictable, and evolves individual actors.
“The immediate question about Boston was domestic or international?” Crowley tweeted on Friday. “It appears to be a hybrid, a homegrown act and international agenda.”